The aquatic growths of lakes, rivers, canals and other waterways present a problem to the operation of the propellers of both outboard and inboard motors of watercraft. Weeds wrap around the propeller shaft and prevent efficient operation.
In the case of an outboard motor, the motor may be tilted out of the water and the weeds manually removed. Inboard motors present more of a problem and require manually removing the weeds from the propeller shaft under water unless the accumulation may be removed by reversing the direction of rotation of the shaft.
Numerous proposals have been made to protect the propeller shaft from aquatic growths. Reference may be made to U.S. Pat. Nos. 2,355,842; 2,470,874; and 2,690,728.